Remedy for glaucoma comprising Rho kinase inhibitor and β-blocker

ABSTRACT

A subject of the present invention is to find utility of a combination of a Rho kinase inhibitor having a novel action and a β-blocker as a therapeutic agent for glaucoma. Actions of reducing intraocular pressure are complemented and/or enhanced each other by combining the Rho kinase inhibitor with the β-blocker. For the administration mode, each drug can be administered in combination or in mixture.

This application is the United States national phase application ofInternational Application PCT/JP03/14559 filed Nov. 17, 2003.

TECHNICAL FIELD

The present invention relates to a therapeutic agent for glaucomacomprising the combination of a Rho kinase inhibitor and a β-Blocker.

BACKGROUND ART

Glaucoma is an intractable ocular disease with a risk of blindness,involving the increase of intraocular pressure due to various factorsand the disorder of internal tissues of eyeballs (retina, an optic nerveand the like). A general method of treating glaucoma is intraocularpressure reduction therapy, which is exemplified by pharmacotherapy,laser therapy, surgical therapy and the like.

For the pharmacotherapy, drugs such as sympathomimetic agents(nonselective stimulants such as epinephrine, α₂ stimulants such asapraclonidine), sympatholytic agents (β-blockers such as timolol,befunolol, carteolol, nipradilol, betaxolol, levobunolol andmetipranolol and α₁-blockers such as bunazosin hydrochloride),parasympathomimetic agents (pilocarpine and the like), carbonicanhydrase inhibitors (acetazolamide and the like) and prostaglandins(isopropyl unoprostone, latanoprost, travoprost, bimatoprost and thelike) have been used.

Recently, a Rho kinase inhibitor was found to serve as a therapeuticagent for glaucoma based on a new mechanism of action (WO 00/09162).Invest. Ophthalmol. & Vis. Sci., 42 (1), 137-144 (2001) discloses thatthe Rho kinase inhibitor increases the aqueous humor outflow from atrabecular meshwork outflow pathway thereby reducing intraocularpressure, and Invest. Ophthalmol. & Vis. Sci., 42 (1), 137-144 (2001)and Invest. Ophthalmol. & Vis. Sci., 42 (5), 1029-1037 (2001) suggestthat the action is due to a change of cytoskeleton in trabecularmeshwork cells.

Combined use of drugs having actions of reducing intraocular pressure totreat glaucoma has already been studied and there are some reports onthe studies. For example, Japanese Patent No. 2726672 reports combinedadministration of the sympatholytic agent with prostaglandins. WO02/38158 discloses a method of treating glaucoma by administering somedrugs having actions of reducing intraocular pressure in combination toeyes.

However, any reports do not describe the Rho kinase inhibitor at all,and naturally, there is no description concerning advantageous effectsbrought about by combining the Rho kinase inhibitor with a β-blocker,either.

As mentioned above, neither study nor report has been made concerningtherapeutic effects on glaucoma obtained by combining the Rho kinaseinhibitor with the β-blocker, so far.

DISCLOSURE OF THE INVENTION

It is a very interesting subject to find utility as a therapeutic agentfor glaucoma due to a combination of a Rho kinase inhibitor and aβ-blocker.

Studying precisely effects due to the combination of a Rho kinaseinhibitor and a β-blocker, the present inventors found that an action ofreducing intraocular pressure is increased and/or persistence of theaction is improved by combining these drugs compared with a case whereeach drug is used alone and consequently completed the presentinvention. Detailed test methods and their effects are described laterunder the item of “Pharmacological Tests”. A remarkable increase inaction of reducing intraocular pressure and/or remarkable improvement ofpersistence of the action was observed by combining a Rho kinaseinhibitor with a β-blocker. The present invention can be suitably usedfor treating and preventing ophthalmopathy accompanied by a rise ofintraocular pressure.

The increase in the action of reducing intraocular pressure and/orpersistence of the action is improved by administering the combinationof the Rho kinase inhibitor and the β-blocker to eyes. Accordingly, thepresent invention is useful as a therapeutic agent for glaucoma.

The present invention relates to a therapeutic agent for glaucomacomprising the combination of a Rho kinase inhibitor and a β-blocker.These drugs complement and/or enhance their actions each other.

For the method of administration, each of the Rho kinase inhibitor andthe β-blocker can be in a separate preparation and these drugs can beadministered in combination. Alternatively, these drugs can beformulated in a single preparation to be administered. In other words,these drugs can be administered in mixture.

The Rho kinase inhibitors and the β-blockers of the present inventioninclude salts thereof. When these compounds have a basic group such asan amino group, they can be salts with an inorganic acid such ashydrochloric acid or nitric acid or with an organic acid with oxalicacid, succinic acid, acetic acid or maleic acid. When they have anacidic group such as a carboxyl group, they can be salts with an alkalimetal such as sodium or potassium or with an alkaline earth metal suchas calcium.

The Rho kinase inhibitors and the β-blockers of the present inventioninclude derivatives thereof such as esters. Specific examples of estersare alkyl esters such as methyl esters, ethyl esters and isopropylesters.

Further, the Rho kinase inhibitors and the β-blockers of the presentinvention can be in the form of hydrates or solvates.

The present invention is characterized by treating glaucoma with thecombination of a Rho kinase inhibitor and a β-blocker.

The Rho kinase inhibitor in the present invention means a compound whichinhibits serine/threonine kinase activated with activation of Rho.Examples of such compounds are the compounds which inhibit ROKα(ROCK-II), p160ROCK (ROKβ, ROCK-I) and other compounds which inhibitproteins having a serine/threonine kinase activity. Specific Rho kinaseinhibitors are exemplified by Rho kinase inhibitors such as(R)-trans-N-(pyridin-4-yl)-4-(1-aminoethyl)cyclohexanecarboxamide and(R)-(+)-N-(1H-pyrrolo[2,3-b]pyridin-4-yl)-4-(1-aminoethyl)-benzamidedisclosed in WO 98/06433 and WO 00/09162, Rho kinase inhibitors such as1-(5-isoquinolinesulfonyl)homopiperazine and1-(5-isoquinolinesulfonyl)-2-methylpiperazine disclosed in WO 97/23222and Nature, 389, 990-994 (1997), Rho kinase inhibitors such as(1-benzylpyrrolidin-3-yl)-(1H-indazol-5-yl)amine disclosed in WO01/56988, Rho kinase inhibitors such as(1-benzylpiperidin-4-yl)-(1H-indazol-5-yl)amine disclosed in WO02/100833, Rho kinase inhibitors such asN-[2-(4-fluorophenyl)-6,7-dimethoxy-4-quinazolinyl]-N-(1H-indazol-5-yl)aminedisclosed in WO 02/076976, Rho kinase inhibitors such asN-4-(1H-indazol-5-yl)-6,7-dimethoxy-N-2-pyridin-4-yl-quinazolin-2,4-diaminedisclosed in WO 02/076977 and Rho kinase inhibitors such as4-methyl-5-(2-methyl-[1,4]diazepan-1-sulfonyl)isoquinoline disclosed inWO 99/64011.

On the other hand, any β-blockers having the action of reducingintraocular pressure and utility in treating glaucoma can be used.β-Blockers having the action of reducing intraocular pressure arespecifically exemplified by timolol, befunolol, carteolol, nipradilol,betaxolol, levobunolol and metipranolol, which have already been on themarket as a therapeutic agent of glaucoma. These are preferably used.

Glaucoma in the present invention includes primary open angle glaucoma,normal intraocular tension glaucoma, hypersecretion glaucoma, ocularhypertension, acute angle-closure glaucoma, chronic closed angleglaucoma, combined-mechanism glaucoma, corticosteroid glaucoma, amyloidglaucoma, neovascular glaucoma, malignant glaucoma, capsular glaucoma,plateau iris syndrome and the like.

To carry out the present invention, preparations can be two preparationsprepared by formulating a Rho kinase inhibitor and a β-blockerseparately or one preparation prepared by mixing these ingredients.Particular techniques are unnecessary for the formulation, and thepreparations can be prepared using widely-used techniques. A preferredmethod of administration is eye topical administration, and a preferreddosage form is an ophthalmic solution or an eye ointment.

When a Rho kinase inhibitor and a β-blocker are formulated inpreparations separately, each preparation can be prepared according toknown methods. For example, the Rho kinase inhibitor can be formulatedin preparations by referring to Formulation Examples described in theabove-mentioned International Publications (WO 00/09162 and WO97/23222). As the preparations of the β-blocker, preparations oftimolol, befunolol, carteolol, nipradilol, betaxolol, levobunolol,metipranolol and the like can be used. These preparations have alreadybeen on the market as the therapeutic agent of glaucoma.

The formulation containing a Rho kinase inhibitor and a β-blocker inmixture can be also prepared according to known methods. The ophthalmicsolutions can be prepared, using isotonic agents such as sodium chlorideand concentrated glycerin; buffers such as sodium phosphate buffer andsodium acetate buffer; surfactants such as polyoxyethylene sorbitanmonooleate, stearate polyoxyl 40, and polyoxyethylene hardened castoroil; stabilizers such as sodium citrate and sodium edetate; andpreservatives such as benzalkonium chloride and paraben, as needed.

The pH should be within an ophthalmologically acceptable range and ispreferably within a range from pH 4 to pH 8. For reference, aformulation example thereof is described below in the section ofExample. However, the formulation example never limits the scope of theinvention.

The present invention also relates to a method of treating glaucomacomprising administering effective amounts of the Rho kinase inhibitorin combination with the β-blocker to a patient. By administering theeffective amounts of the Rho kinase inhibitor in combination with theβ-blocker to the patient, they complement and/or enhance their actionseach other. Rho kinase inhibitors which are suitable for the method oftreatment are(R)-trans-N-(pyridin-4-yl)-4-(1-aminoethyl)cyclohexanecarboxamide,(R)-(+)-N-(1H-pyrrolo[2,3-b]pyridin-4-yl)-4-(1-aminoethyl)benzamide,1-(5-isoquinolinesulfonyl)homopiperazine and1-(5-isoquinolinesulfonyl)-2-methylpiperazine. β-Blockers which aresuitable for the method of treatment are timolol, befunolol, carteolol,nipradilol, betaxolol, levobunolol and metipranolol.

The doses of a Rho kinase inhibitor and a β-blocker can be determineddepending on the symptom and age of patients, the dosage form, theadministration route and the like. The case of instillation is brieflydescribed below. The dose of the Rho kinase inhibitor varies dependingon the drug type. The Rho kinase inhibitor can be administered generallywithin a range from 0.025 to 10,000 μg daily from once to several timesa day. The dose can be appropriately raised or lowered depending on theage and symptom of patients and the like.

The dose of a β-blocker varies depending on drug type. The usual dailydose is within a range from 5 to 5,000 μg, which can be administeredfrom once to several times a day. More specifically, timolol isgenerally administered at a daily dose of 5 to 1,500 μg, befunolol isadministered at a daily dose of 10 to 2,000 μg, carteolol isadministered at a daily dose of 10 to 5,000 μg, nipradilol isadministered at a daily dose of 10 to 1,250 μg, betaxolol isadministered at a daily dose of 50 to 1,000 μg, levobunolol isadministered at a daily dose of 5 to 5,000 μg, and metipranolol isadministered at a daily dose of 5 to 5,000 μg. Depending on the age,symptoms and the like of patients, the doses can be varied. Based onsimilar standards, the doses of the other β-blockers can be determined.

These doses are also applicable to the administration of the combinationof a Rho kinase inhibitor and a β-blocker. In case that a Rho kinaseinhibitor and a β-blocker are to be administrated in one formulation,the formulation should be prepared by selecting the mixing ratio of twodrugs appropriately so that their daily doses might not excess each doseof the separate drugs. The mixed formulation can be administered fromonce to several times daily.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing changes of intraocular pressure with time inrespective administration groups.

BEST MODE FOR CARRYING OUT THE INVENTION

A formulation example and pharmacological tests are shown in thefollowing Examples. The Examples are for better understanding of theinvention but never limits the scope of the invention.

EXAMPLES Formulation Example

A general formulation example of an ophthalmic solution comprising a Rhokinase inhibitor((R)-(+)-N-(1H-pyrrolo[2,3-b]-pyridin-4-yl)-4-(1-aminoethyl)benzamidedihydrochloride) and a β-blocker (timolol) in the present invention isshown below.

Ophthalmic Solution (in 100 mL)

(R)-(+)-N-(1H-Pyrrolo[2,3-b]pyridin-4-yl)-4-(1-aminoethyl)benzamide

dihydrochloride 0.1 g Timolol maleate 0.34 g Boric acid 0.2 gConcentrated glycerin 0.25 g Benzalkonium chloride 0.005 g Dilutedhydrochloric acid quantum sufficient Sodium hydroxide quantum sufficientPurified water quantum sufficient

Ophthalmic solutions having desired combinations and desiredconcentrations can be prepared by changing the kinds and amounts of aRho kinase inhibitor and a β-blocker and by appropriately changing theamounts of the additives.

Pharmacological Tests

So as to study the utility of the combination of a Rho kinase inhibitorand a β-blocker, they were administered to experimental animals,examining the effect on reducing intraocular pressure.(R)-(+)-N-(1H-Pyrrolo[2,3-b]pyridin-4-yl)-4-(1-aminoethyl)benzamidedihydrochloride [Compound A] was used as the Rho kinase inhibitor.Timolol was used as the β-blocker.

Preparation of Test Compound Solutions

1. Preparation of Rho Kinase Inhibitor Solutions

The Rho kinase inhibitor was dissolved in physiological saline, and thensodium hydroxide was added to the solution to neutralize it (pH 6.0 to7.0) to thereby prepare Rho kinase inhibitor solutions having desiredconcentrations.

2. Preparation of β-blocker Solutions

A commercially available β-blocker ophthalmic solution was used as itwas, or was diluted with physiological saline to prepare β-blockersolutions having desired concentrations.

Method of Test

Administering the combination of the Rho kinase inhibitor and theβ-blocker, the effect on reducing intraocular pressure was studied. As areference, administering the Rho kinase inhibitor alone or the β-blockeralone, the effect on reducing intraocular pressure was also studied. Asa control, only a vehicle (physiological saline) was administered.

Drugs and Animals to be Used for Tests

Rho kinase inhibitor solution: 0.1% compound A solution (instillationdosage: 50 μl)

β-Blocker solution: Timolol ophthalmic solution (trade name: Timoptol0.25%, instillation dosage: 50 μl)

Experimental animal: Japanese white rabbit (strain: JW, sex: male, fourrabbits per group)

Method of Administration and Method of Measurement

1. Administration of the combination of a Rho kinase inhibitor and aβ-blocker

1) One drop of a 0.4% oxybuprocaine hydrochloride ophthalmic solution(trade name: Benoxil solution 0.4%) was instilled into both eyes of eachexperimental animal to anesthetize it topically.

2) Intraocular pressure was measured immediately before administeringthe test compound solution, and the intraocular pressure was referred toas initial intraocular pressure.

3) The Rho kinase inhibitor solution was instilled into one eye of eachexperimental animal (the other eye was not treated). Since it isimpossible to instill the β-blocker solution at the same time, after ashort period (about five minutes), the β-blocker solution was instilledinto the same eye.4) One, two and four hours after instilling the Rho kinase inhibitorsolution, one drop of the 0.4% oxybuprocaine hydrochloride ophthalmicsolution was instilled into both eyes to anesthetize them topically.Then intraocular pressure was measured three times to obtain the averageof three measurements.2. Single Administration of a Rho Kinase Inhibitor

Each test was carried out in the same manner as in the above-mentionedcombination administration test except that the β-blocker solution wasreplaced with physiological saline.

3. Single Administration of a β-Blocker

Each test was carried out in the same manner as in the above-mentionedcombination administration test except that the Rho kinase inhibitorsolution was replaced with physiological saline.

4. Control

Each test was carried out in the same manner as in the above-mentionedcombination administration test except that the Rho kinase inhibitorsolution and the β-blocker solution were replaced with physiologicalsaline.

Results and Consideration

Results of the tests are shown in FIG. 1. Intraocular pressure isexpressed in each change from initial intraocular pressure.

As apparent from FIG. 1, the Rho kinase inhibitor and β-blockercombination group exhibited an excellent action of reducing intraocularpressure compared with single administration groups of each drug, namelythe single administration group of the Rho kinase inhibitor and thesingle administration group of the β-blocker, and exhibited improvementof persistence of the action.

When combinations of the other Rho kinase inhibitors and the otherβ-blockers disclosed in the specification were tested, tendenciessimilar to the above-mentioned test results were also observed.

The above-mentioned results show that a stronger reducing effect onintraocular pressure and/or improvement of persistence is obtained bycombining the Rho kinase inhibitor with the β-blocker.

INDUSTRIAL APPLICABILITY

The present invention provides a therapeutic agent for glaucomacomprising the combination of a Rho kinase inhibitor and a β-blocker.

1. A therapeutic agent for glaucoma comprising a combination ofpharmaceutically effective amounts of (i) a Rho kinase inhibitor and(ii) a β-blocker, wherein the Rho kinase inhibitor is(R)-(+)-N-(1H-pyrrolo[2,3-b]pyridin-4-yl)-4-(1-aminoethyl)benzamide andthe β-blocker is timolol.
 2. A method of treating glaucoma comprisingadministering effective amounts of a Rho kinase inhibitor in combinationwith a β-blocker to a patient wherein the Rho kinase inhibitor is(R)-(+)-N-(1H-pyrrolo[2,3-b]pyridin-4-yl)-4-(1-aminoethyl)benzamide andthe β-blocker is timolol.